Sheet handling systems for transporting large sheet-like material between processing stations are well known, as are the class of sheet handling systems referred to as document handlers. For example, U.S. Pat. No. 4,996,556 to Gerald A. Grey, Jr. and assigned to Xerox Corporation discloses a system for receiving large documents, individually, which are then fed into a sheet or document feeder. The document is then transported by the feeder to and through an imaging position to image the document on a photoreceptive surface. The process is repeated until the desired number of images are completed by reverse transport of the document back to the initial imaging position and then recommencement of imaging.
Generally, large document handlers used with devices, such as electrophotographic printing machines, use a preselected path through which documents are moved relative to a process station. In electrophotographic printing machines, one of the processing stations generally employed is an imaging station, which can be, for example, an illuminated imaging slit and lens arrangement for reflecting light from the document onto a charged photoconductive surface to form a latent image.
Mishandling or misfeeding of large documents in the document handler can cause wrinkling, buckling, tearing, or other sheet damage to documents being transported through an imaging station. Such mishandling of the fed documents can also cause the image printed to be skewed, uneven, unevenly magnified, or misregistered due to the failure to present the document properly. Thus, the loading, starting positions, speed (sheet velocity) and direction of movement of the large documents can be quite critical to commercially acceptable imaging, as well as saving the original documents handled.
The following disclosures may be relevant to various aspects of the present invention:
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